Wondering if this lm2678 circuit can handle...

Discussion in 'The Projects Forum' started by fireofenergy, Dec 30, 2011.

  1. fireofenergy

    Thread Starter New Member

    Dec 17, 2011
    Being connected directly to a 12v battery.
    This National semiconductor site makes the diagrams complete with parts list with a tool called Webench (you guys probably already know). I was wondering if the circuit must have an input with limited current, too, or (since it says "for battery chargers"), can be connected to like a car battery?

    The webench link...
    the pdf...

  2. t06afre

    AAC Fanatic!

    May 11, 2009
    What voltage do you want out from the chip? It could de smart to put a fuse on the input as protection. Given that your circuit works as it should. The input current to the chip. Will depend on the load not on the source. So it should be OK to connect to a car battery. Remember that the forum do not allow automative topics. So if put any references saying that you will use the setup in car. The thread will be closed. But almost any use that is not in car(automative) setting will be OK
    Last edited: Dec 30, 2011
  3. fireofenergy

    Thread Starter New Member

    Dec 17, 2011
    Ya, it's actually for solar, a 12v battery charger AND the 12v battery itself, being that the input voltage can be from 8 to 40v (but the webench design was done with 12v min to 22v max, just enough to cover these inputs). It only has like 7 parts (so hopefully, I will learn more about how these parts work).
    The output would be 3.5v at 4A or less (for charging a single 10Ah lifepo4 which will be used to power a 10 watt led).

    Oh, I will definitely use a fuse, thanks for mentioning!